1. Field of the Invention
The present invention relates to a sheet storage apparatus that stores a sheet fed from an image formation apparatus or the like on a stack tray, and more particularly, to improvements in the sheet storage mechanism for enabling sheets to be stored neatly in a correct position on a paper mount surface having a height difference from a sheet discharge outlet.
2. Description of the Related Art
Generally, as this type of apparatus, such a stack mechanism is widely known that a stack tray is disposed on the downstream side of a sheet discharge path and that a sheet is dropped onto a paper mount surface having a height difference from the sheet discharge outlet to store. Then, such a post-processing mechanism is also known that a sub-tray is provided between the sheet discharge outlet and the paper mount surface to temporarily hold a sheet, the sheet undergoes post-processing such as binding processing, paper folding processing and punching processing on the tray, and that the processed sheet is stored on the paper mount surface.
For example, Patent Document 1 (Japanese Patent Gazette No. 4901082) discloses an apparatus in which a stack tray is disposed in a sheet discharge path of an image formation apparatus, support members are provided between a sheet discharge outlet and a paper mount surface to support the sheet rear end and sheet corner, and that binding processing is performed on a bunch of sheets collated and collected on the support members to store on the paper mount surface. In the apparatus in the Document, the rear end support member for supporting the sheet rear end and corner support member for supporting the sheet corner are disposed between the sheet discharge outlet and the paper mount surface, and the apparatus is provided with a shift mechanism that causes both support members to reciprocate between actuation positions above the tray and waiting positions outside the tray.